1. Field of the Invention
The present invention relates to an apparatus for controlling the positioning of a recording/reproducing apparatus and, in particular, a method and apparatus for controlling the positioning of a magnetic head of a magnetic recording/reproducing apparatus using both a battery drive mode and commercial power source drive mode.
2. Description of the Related Art
Recently, hard disc apparatus and floppy disk apparatus, for example, have been developed as compact units and are utilized as external memory devices for mini-computers, compact word-processors, etc.
Some mini-computers and compact word-processors are of a battery drive type and, therefore, a battery-powered device has been developed for compact hard disc devices.
In the hard disk devices, for example, a voice coil motor is used to control the positioning of a magnetic head in which case a substantially proportional relation exists between the access speed (the seek speed of a magnetic head) and the dissipation current. In the battery drive mode, the dissipation power on the hard disk apparatus should be restricted due to the restricted battery power capacity. Thus the battery-powered hard disk apparatus involves a reduced access speed.
It has been customary to, even upon the use of the battery drive system, employ a commercial power source of a greater power capacity in combination with it. If the access speed suitable for the commercial power source drive system is used, it will be necessary to use, in the case of the battery drive system, a battery of a great power capacity corresponding to that of the commercial power source system.